1. Field of the Invention
This invention relates to high performance explosive compositions that are pressable or extrudable, and to devices and apparatuses using the explosive compositions as an explosive ingredient for high performance, low sensitivity explosive applications. More specifically, this invention relates to high performance explosive compositions comprising CL-20, energetic plasticizers, and high molecular weight non-energetic polymeric binders.
2. Description of the Related Art
Among the litany of high performance explosives that have been used in ordnance and other high impact applications, a relatively new explosive known as CL-20 has been recognized for its superior energy levels that far surpass those of most conventional explosives. CL-20, is referred to commonly as (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.0.sup. 5,9.0.sup.3,11 ]-dodecane and 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane.
Examples of explosive formulations containing CL-20 as the primary explosive component are disclosed in both U.S. Pat. No. 5,587,553 to Braithwaite et al. and U.S. Pat. No. 5,712,511 to Chan et al. As touched upon in the Chan et al. '511 patent, which relates to explosive compositions for deformable-type warheads and directional ordnances, CL-20 is extremely sensitive to physical impact. Indeed, CL-20 has been associated with high electrical and thermal sensitivities as well. The highly sensitive nature of CL-20 may lead to premature detonation in ordnance applications. The Chan et al. patent apparently compensates for the high sensitivity of CL-20 by incorporating it into high energy shock-insensitive explosive compositions comprised of a relatively low concentration of CL-20, e.g., from about 35 wt % to about 45 wt %.
In contrast, the Braithwaite et al. patent seeks to improve the high performance of the CL-20 explosive by using it in high concentrations and in combination with high molecular weight liquid energetic polymers, especially chain-extended polyglycidyl nitrate (PGN). It has also been known to use CL-20 in combination with other polymers. One such combination commonly known as LX-19 combines CL-20 with ESTANE (C.sub.5.14 H.sub.7.5 N.sub.0.187 O.sub.1.76). The performance characteristics, e.g., energy levels, exhibited by LX-19 are generally considered to be excellent. However, the impact, electrical, and thermal sensitivities associated with LX-19 and other formulations using CL-20 in combination with energetic binders are considered to be too high for some applications.
It would, therefore, be a significant advancement in the art to provide a plastic bonded explosive formulation that contains a sufficient amount of CL-20 to exhibit equal or better high energy performance than LX-19, yet which has sufficiently low impact, electrical, and thermal sensitivities to permit the formulation to be used for a variety of applications without an unacceptable risk of unintentional or premature detonation.